A method for correcting the velocity deviation between the actual pulling up rate and nominal pulling rate during crystal growth

摘要

PROBLEM TO BE SOLVED: To provide a method for correcting speed deviations between an actual pull speed and a nominal pull speed during crystal growth in the production of a single crystal silicon by Czochralski process, and to provide a mechanism of pulling a crystal for the method.;SOLUTION: A processor determines a change in the position of a crystal pulling mechanism when the crystal pulling mechanism travels at an actual speed, implements a filter function, and estimates a new filter state relating to the filter function based on the change in the detected position. The processor estimates a new position of the crystal pulling mechanism by using the estimated new filter state, determines a position estimation error, and determines a filter gain of the next filter state relating to the filter function. Then the processor corrects an actual speed of the crystal pulling mechanism during the next period by using at least one estimated filter gain relating to the next filter state.;COPYRIGHT: (C)2011,JPO&INPIT